1. Field of the Invention
This invention relates to security systems as used to monitor portable devices and, more particularly, to such a system with an electronic sensor that is attached to each such device.
2. Background Art
Electronic security systems are used in many retail establishments to monitor portable devices that are prone to being discretely removed from the premises at which they are displayed. Electronic devices, which continue to become more compact in size and expensive in nature, are particularly vulnerable in retail establishments whereat they are displayed in large numbers for hands-on inspection and operation by potential purchasers.
The multitude of competing manufacturers and different designs offered by each has caused displays often to be crowded with a particular type of product. For example, a single display may accommodate dozens of digital cameras made by different distributors and offered with many different features and in many different price ranges. The cost of these cameras generally warrants the investment in sophisticated electronic security systems.
In a typical retail establishment, a display of the above type will be designed with a discrete number of stations, each capable of accommodating a single device at which informational materials can be displayed to be visible in close proximity in association with the device. The security system, while normally adaptable to change the number of devices that it will accommodate, is typically set up so that the number of sensors corresponds to the number of stations. Preparatory to placing the security system in an armed state, the sensors are attached, one each, to a device at a station and are changed from an unsecured state into a secured state. This is commonly accomplished by adhering the sensor directly to the device in a manner whereby a captive actuating plunger is repositioned to change the state of the sensor.
The controller on the security system may be designed so that the system can be armed only once the active sensors are in their secured states. This feature avoids situations whereby the overall system may be armed but individual sensors remained in an unsecured state, due to improper sensor attachment or malfunction, whereby the associated devices are vulnerable to theft.
Other systems do not incorporate this feature and have controls that allow the arming of the system while certain sensors remain in place but unattached to a device at a particular station. This capability may be desirable from the standpoint that it gives greater system flexibility. That is, no special measures need be taken in the event that there are one or more stations at which there is no device displayed. At the time that the system is placed in the armed state, the controller will detect the unsecured state of one or more of the sensors and nonetheless permit arming of the system.
This latter design is particularly desirable from the standpoint of convenience and system integrity. In the absence of this feature, the system operator would be forced to make a manual adjustment, as by putting a shunt in a port accommodating the inactive sensor(s), or otherwise programming or adapting the system. This is inconvenient since often the controller for the system is placed within a closed cabinet so that it is not easily accessible, with the objectives thereby of contributing to aesthetics and avoiding controller tampering.
With this type of system, the sensor that is in the inactive state may cause a detectable alarm signal to be generated in response to the changing of the position of the plunger on the sensor with the system in the unarmed state. If for any reason, intentional or unintentional, the plunger on the inactive sensor(s) is repositioned, an alarm will be triggered. This condition may cause embarrassment to a potential customer and is an inconvenience to personnel at the particular establishment. This may cause an operator to disable the entire system, exposing the displayed devices to theft.
The main objective of designers of the above types of systems is to devise systems that are reliable in performance. Secondly, they must be “user friendly”. If the system is inconvenient to operate or has “quirks” that translate into user inconvenience, employees may be inclined to avoid arming of the system, whereby the entire collection of displayed devices is prone to being removed by a thief. In line with this latter objective, the system should be versatile enough to allow the convenient selective placement and re-placement of devices at, and removal of the same from, individual stations. If a system compromises the ability to effectively display products for potential consumers, those involved in using such systems may be tempted to bypass them, thereby negating the value of the investment in the system and exposing the associated devices to theft.
The industry continues to seek designs of security systems that effectively meet the above objectives.